But what if any window in your home or office could be turned into a solar power source?

Think about it… Someday your window could power your air conditioner on a hot day or your heater when it’s freezing outside—all by harnessing, trapping, and converting sunlight into electricity.

Researchers at the Department of Energy’s Los Alamos (N.M.) National Laboratory are working on it—they are developing a new sunlight harvesting technology that can turn a nearly transparent window into an electrical generator using what they are calling “quantum dot solar windows.”

“In these devices, a fraction of light transmitted through the window is absorbed by nanosized particles (semiconductor quantum dots) dispersed in a glass window, re-emitted at the infrared wavelength invisible to the human eye, and wave-guided to a solar cell at the edge of the window,” Victor Klimov, lead researcher on the project at the Department of Energy’s Los Alamos National Laboratory, says in a Los Alamos National Laboratory news release. “Using this design, a nearly transparent window becomes an electrical generator, one that can power your room’s air conditioner on a hot day or a heater on a cold one.”

This technology could turn any window into a daytime power source, converting sunlight into electricity. Credit: Los Alamos National Laboratory

Klimov and his team at the Center for Advanced Solar Photophysics (CASP) of Los Alamos published the study of this new technology in the journal Nature Nanotechnology in partnership with Sergio Brovelli and Francesco Meinardi of the Department of Materials Science of the University of Milan-Bicocca (UNIMIB) in Italy.

Previous studies using quantum dot technology were “based on the toxic heavy metal cadmium and were capable of absorbing only a small portion of the solar light. This resulted in limited light-harvesting efficiency and strong yellow/red coloring of the concentrators, which complicated their application in residential environments,” according to the news release.

Klimov and his team’s updated approach solves both the coloring and toxicity problems by using “a complex composition which includes copper (Cu), indium (In), selenium (Se) and sulfur (S),” Klimov explains in the news release. “Importantly, these particles do not contain any toxic metals that are typically present in previously demonstrated LSCs.”

“Furthermore, the CISeS quantum dots provide a uniform coverage of the solar spectrum, thus adding only a neutral tint to a window without introducing any distortion to perceived colors,” Klimov notes in the release.

And Klimov’s team isn’t the only group focusing their research on developing solar cells that are better at converting sunlight into electricity. A recent article published in the American Chemical Society’s journal ACS Nano describes how scientists are developing a new hybrid system that harnesses more sunlight by pairing a photovoltaic cell with devices that turn heat into electricity. (Check out this brief ACS video that demos the technology!)